FR2841301A1 - Automobile starter motor has pinion comprising toothed part meshing with starter crown wheel and driver coupled to pinion by conical clutch - Google Patents

Abstract

The starter comprises a starter motor provided with a pinion (1) comprising a toothed part for meshing with a starter crown wheel and a driver (2) coupled to the pinion by a conical clutch having friction surfaces (8,8'). The pinion comprises a sintered material part and the driver comprises a plastic material part reinforced by fibers.

Description

4a8. The present invention relates to vehicle starters

  automobiles, and more specifically to launchers that include such starters. As illustrated in Figure 1, a motor vehicle starter conventionally comprises a contactor 12 and an electric motor M adapted to drive directly or indirectly, here via a reducer, an output shaft 100, which carries a launcher equipped with 1. The pigeon 1 is intended to cooperate with the gearing of the starter ring C of the internal combustion engine of the motor vehicle. It is slidable on the output shaft between a rest position where it is disengaged from said starter ring and an advanced position where it meshes with

  this one being in support on a stop of work 6.

  The contactor 12 extends parallel to the electric motor M to

  above it and comprises a winding 12a and a plunger core 12b.

  11 controls the supply of the electric motor M by moving a movable contact 13 between an open position and a closed position, said contact 13 being pushed by said plunger core 1 2b axially movable relative to the electric motor M when the

winding 12a is active.

  The switch 12 also controls the movement of the pigeon 1.

  Its plunger core 12b is for this purpose connected to the pigeon 1 by means

  mechanical references by 14 as a whole.

  These mechanical means comprise a fork-shaped control lever coupled at its upper end to the plunger core 12b and at its lower end to a trainer also belonging to the launcher. The trainer is provided with a training sleeve having a groove for receiving the fork. The fork accompanies the launcher

  towards his advanced work position of the pigeon.

  The launcher also has a freewheel interposed axially between the drive socket and the pigeon 1. The drive sleeve is internally provided with helicoidal channels in a complementary manner with external helicodal teeth carried locally by the output shaft entrained by the electric motor M when

  it is powered electrically.

  The fork is pivotally mounted between its two ends on a housing internally containing the mechanical means 14 and carry the motor M and the switch 12. The launcher with its pigeon 1 is animated by a helicoidal movement when it is moved by the fork

  to engage with the starter crown.

  This is achieved by feeding the winding 1 2a following an actuation of the ignition key which makes it possible to set the plunger 12b in motion then attracts towards a fixed core mounted at the end of a winding support 12a . This support has a U-shaped section for housing the coil 1 2a and thus comprises a bottom constitute a pad 12C. The core 12b is therefore intended to move between a rest position and a contact position in which it is supported on the fixed core; this closing position of the magnetic circuit taking place after closure of the moving contact 13 and thus the

electrical circuit.

  The mechanical means also comprise a return spring mounted around the core 12b to return the latter in the rest position, a breaking spring associated with the movable contact 13 to return the latter in the open position and a spring 15, said spring teeth against teeth, housed inside the core 12b and engaged with a first rod connected by an axis at the upper end of the fork for coupling thereof to the core

  12b. This spring 15 has a greater stiffness than the return spring.

  The fork is therefore inserted at its upper end between the core 12b and the axis. The first rod is mounted inside a blind hole of the core 1 2b. The core 1 2b is intended after a determined race to come into engagement with a second rod secured to the movable contact 13 and slidably mounted inside the fixed core. In the closed position the contact 13 cooperates with a fixed contact, in the form of pads respectively connected to the positive terminal of the battery and the motor

  M electric, thus allowing the power of the electric motor.

  The wind studs integral with the closing cap of the contactor

insulating material.

  All these elements are shown in Figure 1 and have not been

all references by simplicity.

  The pigeon 1 can therefore come into engagement with the crown C, that is to say come into gearing position with the crown C, before the contact

mobile is not firm.

  Most often the pigeon 1 comes axially in contact with butee

  with teeth of crown C before entering it.

  Thus the mechanical means 14 comprise in particular the spring, which is mechanically interposed between the plunger core 12b and the pigeon 1 and which allows the plunger 1 2b to continue its stroke to ensure, before contact with the fixed core, the setting in position closing of the movable contact, even if the pigeon 1 is blocked against the teeth of the crown of the engine in a position where it

do not mesh with this crown.

  As the freewheel, interposed between the pigeon 1 and the starter socket, has the main function to prevent that, when the internal combustion engine of the vehicle starts, the pigeon 1 drives the engine

  electrical speed at a speed too high likely to deteriorate the latter.

  The rollers that comprise the freewheel each subjected to the action of a circumferential action spring so that it damps the sudden vibrations of the torque that is transmitted between the bushing.

training and the pigeon 1.

  In order to reduce the size, the weight and the cost of the freewheel in relation to its use, it has been proposed in document FR A 2,772,433 to involve a coupling device with a clutch of the conical type between the pigeon and the trainer to harness the pigeon to the pitcher. In practice, the pigeon and the driver respectively each carry a first frustoconical friction surface and a second frustoconical friction surface respectively. These coaxial friction surfaces have a complementary shape and wind in contact with each other, with a predetermined value of effort, by means of elastic means with axial action supported in a form of realization on a first stop. integral with the free end of a skirt belonging to a ring-shaped coupling piece for action on a second stop integral with the trainer so that the trainer can slide in rotation relative to the pitcher's pigeon when the speed of

  rotation of the pigeon is superior to that of the coach.

  The average diameter of the friction surfaces is substantially equal to the diameter of the pitch circle of the pitcher's pigeon teeth, while the first frustoconical friction surface belongs to an axial extension of the pigeon. In practice the coupling part consists of a coupling cowl having at its outer periphery an annular skirt directed axially towards the driver being cylindrical in shape and axially oriented. This hood has a bottom axially supported on a

  oversize the axial extension of the pigeon.

  This provision is satisfactory, however it may be desirable, in a simple and economical way, to further increase the efficiency and reliability of operation of the coupling device.

conical clutch.

  The present invention aims to meet this wish.

  According to the invention, a starter with a tapered clutch coupling device of the type indicated above is characterized in that the first frustoconical friction surface is borne internally by the skirt of the coupling piece, in that that the bottom of the coupling piece is integral with the pigeon and in that the mean diameter of contact of the first frustoconical friction surface with the second frustoconical friction surface is greater than the diameter of the pitch circle of the

pigeon's teeth.

  Advantageously led it d iametre average is superior to d iametre of the

head circle of the pigeon's teeth.

  This average diameter is. in case of overspeed of the pigeon compared to the coach, a mean diameter of friction. The conical clutch according to the invention is securely blocked when the electric motor of the starter drives the internal combustion engine of the vehicle via the starter ring and is adapted to unlock when the internal combustion engine drives the pigeon at a speed. higher rotation

  (overspeediness) to that of the coach.

  Thanks to the invention the effectiveness and reliability of the wind launcher increases because the average diameter of the first frustoconical friction surface is greater because this first surface belongs to the skirt of the coupling piece implanted on a larger diameter as the diameter of the head circle of the pigeon. This increases the average diameter of the first frustoconical friction surface with respect to the diameter of the splines of the output shaft of the starter carry the trainer. Of course, the average diameter of the second frustoconical friction surface is also increased because the two frustoconical friction surfaces wind coaxial and complementary; the second surface penetrating inside the first surface. These two surfaces

  frustoconicals have the same cone angle.

  Thus, thanks to the invention for a diametral size gives the launcher the first friction surface and the second frustoconical friction surface will therefore each have the largest average diameter.

friction possible.

  Advantageously, the first frustoconical friction surface of concave shape is longer axially than the second frustoconical friction surface of convex shape and completely surrounds it.

  which further reduces the axial size of the launcher.

  In all cases, the coupling piece protects, by means of its skirt and also from its firmly sealed bottom of the pigeon, the frustoconical friction surfaces and prevents them from being soiled.

  for example by oil and water.

  The operation of the launcher is thus gable and of great duration

of life.

  The fact that the coupling piece is integral with the pigeon makes it possible to reduce the axial size of the launcher, in particular because the bottom of the coupling piece does not extend over the thickness and also simplifies the

mounting the launcher.

  Indeed, the pigeon and the hitch are a sub-

  manipulable set, transportable and captive. This soul-set is of comfortable assembly with the second soul-set made up by the trainer. In addition it is possible to realize the soul-assembly pigeon-piece hitch monoblock manner or in several parts preferably in a different matter adapted to the function to be achieved. It is the same

1 0 the trainer.

  It will also be appreciated that the weight and cost of the launcher is reduced by the fact that the first friction surface belongs to the light and economical hitch. The pigeon is no longer extended axially and no longer has the first friction surface so

  that it is simpler and more economical.

  The trainer also has a simpler and more economic form because it no longer has a recess for the penetration of an axial extension of the pigeon carry the first frustoconical friction surface because it is the skirt of the coupling piece. which carries this first surface of friction. The trainer is more robust since the solution according to the invention makes it possible to remove the ferrule from FIGS. 3 and 5 of the document.

FR A 2 772 443 specifies.

  Thus, according to a characteristic, the second abutment surface is integral with a transverse shoulder delimiting axially the second

frustoconical friction surface.

  This provision makes it possible to further simplify the coach and

  to increase the mechanical hold of it.

  It also allows to realize the trainer by molding a base

  of plastic material and thus to lighten it.

  In addition, the elastic means with axial action exert an action on the trainer according to an average diameter close to the average diameter of the second frustoconical friction surface. In one embodiment, the mean diameter of action of the elastic means with axial action is generally equal to the smallest diameter of the second surface of

frustoconical friction.

  The action of the elastic means with axial action on the trainer therefore takes place in a thick zone thereof, which is particularly favorable for their implantation. Advantageously, the skirt is of frustoconical shape to reduce

  still the size and weight of the launcher.

  In one embodiment, the first stop is borne by an extension of the tubular skirt constituting the free end of the

hitch.

  The tubular extension has an axial length which depends on the applications and in particular on the axial thickness of the elastic means with axial action and makes it possible not to increase the radial size of the

  launcher while facilitating the mounting of the launcher.

  More specifically, this tubular extension serves as a simple way of fixing a system for holding and closing the complete launcher, said system comprising the first stop and the elastic means a

axial action.

  In one embodiment, the mean friction diameter eVu of contact between the frustoconical friction surfaces is equal to or greater than

  % of the diameter of the tubular extension of the skirt.

  Other features, purposes and advantages of the invention

  will appear on reading the detailed description which will follow, made in

  reference to the appended figures, in which: - Figure 1 shows a motor vehicle starter according to the state of the art; FIG. 2 schematically represents the forces acting within a launcher according to the invention when the starter drives the internal combustion engine of the motor vehicle; FIG. 3 is a view in axial section of the launcher for a first embodiment according to the invention; FIGS. 4, 5 and 6 show views similar to FIG.

  three other embodiments according to the invention;

  - Figure 7 is a front view of the circlip-shaped elastic means of Figure 6; FIGS. 8 and 9 respectively show a front and side view of another embodiment of the resilient means of FIG. 7. In FIGS. 2 to 7, in particular to reduce the number of pieces of the launcher to be assembled in the end. according to the invention, the launcher of FIG. 1 is replaced by a launcher equipped with a pigeon 1 (FIGS. 3 and 6), 10 (FIGS. 4 and 5) secured to a coupling piece, and its outer periphery a first frustoconical friction surface cooperating in a complementary manner and coaxial with a second frustoconical friction surface carried by the trainer (reference 2 in Figures 2 to 6)

  for forming a conical clutch (reference 7 in Figure 2).

  The tapered clutch and the coupling part, of annular shape, belong in the aforementioned manner to a coupling device

  between the trainer 2 and the pigeon 1.10 to harness the pigeon to the coach.

  According to a feature of the invention the coupling piece is via its

solid bottom of the pigeon.

  More precisely, the first frustoconical friction surface, referenced at 8 in FIG. 3, is borne by the internal periphery of a skirt of the coupling piece of annular and hollow shape, the bottom of which is integral with the pigeon of the launcher, possibly in several parts advantageously of different material adapted to their own function, and is centrally hole for passage of the output shaft 100 as visible in Figure 2. The coupling piece is produced for example economically by stamping a tole. Alternatively the coupling piece is more massive. The skirt of the coupling piece is directed axially towards the coach. The trainer has at its inner periphery, as in Figure 1, helicoidal grooves in engagement with helical grooves carried by the outer periphery of the shaft 100. Helicoidal grooves 9 intervene thus complementarily between the shaft

and the trainer2.

  The skirt connects to one of its axial ends, quoting the first axial end, to the outer periphery of the overall orientation bottom.

  cross section of the coupling.

  In a first embodiment the skirt is massive in being annular and axially oriented at its outer periphery. Externally the skirt is cylindrical and internally shaped

  frustoconical to carry the first frustoconical friction surface.

  In another embodiment, as represented in FIGS. 2 to 6, for further reduction of the mass of the launcher, the skirt is frustoconical in shape, preferably of constant thickness so that the

  hitch is generally bell-shaped.

  According to a feature of the invention the skirt is extended axially beyond the axial end of larger diameter, said outer diameter, of the first frustoconical friction surface by an annular end zone of axial orientation (1c in Figures 3 and 6, c in Figures 4 and 5). The annular zone 1c, 20c therefore forms a tubular extension of the first surface 8 of the skirt internally

  flared shape towards the coach.

  This zone 1c, 20c, of cylindrical shape, delimit the second axial end of the skirt, that is to say its free end, and carries a first stop 4 extending radially inwardly that is to say transversely. According to a characteristic, the zone 1c, 20c extends in axial projection with respect to the second surface 8 '. The transverse stop 4 here consists of a circlip, alternatively a snap ring, mounted in a groove made on the inner periphery of this zone 1c, 20c constitute the free end of the skirt and the coupling piece. In FIG. 6, in the manner described hereinafter, the precise circlip has an additional function because it has protruding circumferential tongues at its inner periphery.

axially and elastically.

  The presence of a throat is not obligatory. Thus alternatively the first stop is a washer fixed by crimping on the end of the zone 1c, 20c advantageously then metal. To do this, the stop 4 has at its outer periphery radially projecting steps each of which is complementarily engaged in a notch at the end of the zone 1c, 20c. The lateral edges of the notches are then deformed with creep of material to locally cover the pastes in contact with the bottoms of the notches for example U-shaped section. In another variant Ie butee 4 is fixed by welding on the end of the zone 1c, 20c. For example, the welding is carried out between the lateral edges of the notches and the circumferential ends of the pastes

of the abutment 4 above.

  It will be appreciated that the fasteners by crimping and welding can increase radially the size of the stop 4 which allows better seal the space between the stop 4 and the trainer close the free end of the cavity delimited by the piece hitch. The stop 4 then has a protective function because it masks elastic means to action

axial 3.

  These elastic means with axial action 3 are supported on the stop 4 for action on a second radial stop 4 ', that is to say transverse, integral with the drive 2 and clamping of the second frustoconical friction surface, reference 8' in Figure 2, integral with the trainer being in contact in a complementary manner and coaxial with the first surface

  frustoconical friction integral with the skirt and thus the pigeon launcher.

  The second frustoconical surface 8 'is of convex shape, while the

  first frustoconical surface 8 is of concave shape.

  Here the first surface 8 completely surrounds the second surface 8 '. These surfaces 8,8 'have an average diameter greater than the diameter of the head circle of the pigeon 1,10 so that the average diameter of friction or contact of the two surfaces 8,8' is greater than the head circle of the pigeon's teeth. . The efficiency and reliability of operation of the launcher is therefore increased. The axial size is also reduced. In addition, the wear of the surfaces is made up, the first surface 8 having a characteristic longer axially than the second surface so that the trainer can get closer to the pigeon and the axial size of the launcher is reduced. The mean diameter of contact and friction between the two friction surfaces 8, 8 'is thus equal to the average diameter of the second surface 8' having at its axial end adjacent to the elastic means 3 a larger diameter than its other axial end. smaller diameter. The average diameter is therefore located in the middle of the axial length of the second surface 8 ', the first surface 8 extending axially on either side of the second surface 8'. The elastic means 3 also belongs to the coupling device and more precisely belong with the first stop 4 has a

  system for maintaining and closing the complete launcher.

  Thus, firstly, a first assembly comprising the pigeon and the coupling piece provided with the first surface 8 is produced, and a second assembly is formed by the trainer provided at its outer periphery with the second surface 8 ', and then bring the coach closer to the first soul-set by threading the second surface in the first surface, then we put in place the elastic means 3 and finally

  we lock everything by setting up the stop 4.

  These elastic means 3 here consist of a corrugated washer, alternatively a washer of the Grower type, the Belleville washer type, fan type type claws or even a coil spring advantageously frustoconical shape. In a variant, these means 3 may comprise several elements mounted in series such as Belleville washers. Alternatively it may be a wavy washer extending over

more than 360.

  These elastic means 3 wind implants axially compression between the first stop 4 and the second abutment 4 'carried here, to further reduce the axial size of the launcher, by a transverse shoulder of the drive delimiting according to a feature axially the second surface 8 'at its largest diameter. The shoulder is formed by means of an annular removal of material to the outer periphery of the body of the trainer for accommodating at least part of the elastic means 3. This removal of material is delimited by the transverse shoulder 4 ' and by an annular door axially oriented 4 "connecting to the inner periphery of the shoulder 4 'and allowing a centering of the elastic means 3 by intimate cooperation with the inner periphery thereof.The elastic means 3 wind boxes here entirely in the lifting of matter and are treated as directly on the surface 4 'or indirectly on it in favor of a coating.

  the abutment 4 'is borne by the shoulder.

  Of course, alternatively, when problems of radial space do not arise, the first stop 4 is carried by a zone extending the first surface 8, which makes it necessary to increase the radial size.

from the first stop 4.

  As a variant, for reducing the number of pieces, this first stop is formed by a folding of material of the free end of the zone 1c, 20c of preference before setting up the elastic means with axial action 3. Advantageously, these elastic means consist of then in a flat washer provided at its external periphery with frustoconical loops elastically deformable to cross by deformation the first butee

  and then exert an axial thrust on the flat washer.

  In a variant, again for reducing the number of pieces, it is the franc of the throat of the zone 1c, 20c furthest away from the surface 8, which constitutes the first radial stop, the elastic means 3 having, in the aforementioned manner, truncated. Alternatively the corrugated washer 3 has at its outer periphery at least two radial steps each adapted to pass through an axial passage formed at the inner periphery of the zone 1c, 20c to lead into the aforementioned groove to achieve by

  translation and rotation a mounting type bayonet.

  All possible wind combinations, the launcher having two

  soul-sets and one or two additional rooms 3.4.

  In all cases, the elastic means 3 wind mounted under prestressing between the stops 4,4 'and allow to maintain in pressure the second frustoconical surface 8' of the trainer against the first frustoconical surface 8 integral with the pigeon 1,10. Note that the average diameter of the first stop 4 is greater than the average diameter of the second

stop 4 '.

  The elastic means 3 exert a predetermined force of

  relatively falble value that depends on the applications.

  More precisely, this initial pressure produces a friction torque between the lortranger and the pigeon which is always, by construction, greater than the torque necessary for the screwing and the advancement of the launcher.

the tree 100.

  This condition allows self priming, the age of the movement of the launcher between its rest position and its advanced position against the work stop, referenced in 6 in Figure 2, at the beginning of the phase of driving the engine of the vehicle via the boot rim. When the pigeon reaches the stop 6 there is compression of the surfaces 8, 8 'against each other with a blockage This blockage of movement between the pigeon and the launcher depends in particular on the angles and diameters of the friction surfaces

1 5 frustoconical.

  As can be seen in FIG. 2, during the driving of the internal combustion engine of the motor vehicle by the electric motor of the starter the torque Cd generated by the starter at the output shaft 100 carries the drive 2 and transforms by the device with helical grooves 9 intervening between the drive 2 and the shaft 100 - creates a force

axial Fa.

  This force Fa is itself decomposed at the level of the frustoconical friction surfaces to create a normal contact force Fc, which generates a tangential force Ft to the frustoconical surfaces 8, 8 'as a function of the coefficient of friction between these surfaces. The value of this force Ft multiplied by the average contact radius of the friction surfaces

  frustoconical determines the torque Ce transmitted by the conical clutch 7.

  For the pigeon to train normally without slipping it is necessary

  that the relation Ce> Cd remains always true.

  All this depends on the applications because the coefficient of proportionality between Cd and Fa depends on the angle of inclination of the grooves 9, the mean radius of these grooves and the coefficient of

  sliding between the output shaft 100 and the coach.

  The proportionality coefficient between F and Fc depends on the angle of

  cone between the two frustoconical friction surfaces.

  The value of Ft is related to Fc and to the coefficient of friction fc between the two materials of the frustoconical friction surfaces of the clutch 7. To avoid any jamming, the tangent relation (a)> fc, in which a is the value of the half-angle at the top of the contact cone between the frustoconical friction surfaces and f'c the coefficient of adhesion. All these values are calculated according to formulas of the

  mechanics known per se and depend on the applications.

  These formulas involve the coefficient of friction between the splines of the shaft and the drive, the mean radius of the splines,

  The cone angle of the surfaces 8,8 'and the coefficient of friction thereof.

  All this influences the choice of materials for the coach, the skirt and the

1 5 pigeon.

  When the engine of the vehicle to start the pigeon 1 rotates faster than the output shaft 100 which allows the unloader launcher on the shaft 100. The axial force previously transmitted disappears and there remains only the couple residue! falble the elastic means 3 which is transmitted to the electric motor of the starter. During this overspeed phase stroke the clutch 7 behaves as a freewheel device with a relative movement between the surfaces 8,8 '. The mean diameter of contact between the two surfaces 8, 8 'is therefore also a diameter of friction in

overspeed.

  The hitch allows to link the trainer to the pigeon via

  the frustoconical friction surfaces and replaces the cover of Figure 1.

  The coupling piece is integral with the pigeon being in one piece with

  this one (FIGS. 2, 3 and 6) or reported for attachment thereto (FIGS. 4 and 5).

  The walls of the coupling piece (its bottom and skirt) are continuous so that the coupling part is waterproof, no opening exists between the

  bottom of the hitch and the pigeon.

  For simplicity in the figures ['pigeon set - coupling piece

will be called pigeon bell.

  Thus in Figures 2, 3 and 6 the pigeon bell is in one piece being in one material or bi material, while in Figures 4 and 5 the bell pigeon is in two pieces 10,20, namely the pigeon and the bell 20; each piece being then chosen in an optimum manner according to its function to achieve. In all the figures, the bell pigeon comprises, on the one hand, a dentee portion constituting the pigeon, referenced at 1 in FIGS. 3 and 6 and at 10 in FIGS. 4 and 5, and on the other hand, a frustoconical portion, reference in 1 ba in Figure 3 and in 20b in Figures 4 and 5 belonging to

at the hitch.

  The dentee portion is tubular in shape and has in section the generally bomb-shaped sidewall-shaped teeth necessary for engagement with the starter ring of the internal combustion engine of the motor vehicle. The pigeon thus presents teeth defined in known manner by a party circle, a primitive circle and a foot circle. It is the internal periphery of the frustoconical part which constitutes

  directly or indirectly the first frustoconical friction surface.

  Indeed, the internal periphery of the frustoconical portion 1b, 20b can rub directly against the second frustoconical friction surface belonging to the drive or indirectly against the second friction surface friction, I at least one of the d surfaces of frustoconical friction then being provided with a coating such as a friction lining fixed for example by gluing. This allows to control in particular

the force Ft mentioned above.

  As a friction or friction lining, it is possible to use a lining of the type described in EP A 0 816 707 comprising a fiber mat impregnated with a thermosetting resin. These fibers are carded to form a carafe veil and advantageously have a length of at least 40 mm. Glass, for example, is incorporated in the mat. For more details, please refer to this document. With this type of packing, remarkable stability is achieved

  the coefficient of friction of the material as well as small wear.

  The first frustoconical friction surface therefore belongs to the inner periphery of the skirt of the coupling piece or is reported on

said internal periphery.

  It is the same with the second frustoconical friction surface, which is formed either directly by the external periphery of a frustoconical door belonging to the trainer 2 or is reported on said bearing

from the outer periphery.

  In all cases at least one of the two frustoconical surfaces 8,8 'has grooves extending from one axial end to the other axial end of the frustoconical surface concerned and this in a rectilinear or curved manner. In a variant, the grooves extend circumferentially. A network of crooked circumferential and straight curved eVou grooves can be realized. This network may comprise circumferential grooves connected to the axial ends of the frustoconical surface concerned by distinct grooves extending in a rectilinear or curved manner. All possible wind combinations For example the wind grooves at the outer periphery of the second

  surface, alternatively to the inner periphery of the first surface.

  Thanks to the grooves, the dust is evacuated and the two surfaces are separated from one another, particularly in

overspeed.

  Likewise on conventional launchers' pigeons, the teeth of the parts dentees 1.10 wind preferably provided at their free end, side opposite to the coach 2, of a chamfer to facilitate the penetration of the

  pigeon in the start crown visible at C in Figure 1.

  In these Figures 2 to 5 the bottom of the coupling piece, and therefore the bell, is of transverse orientation in so that it extends perpendicular to the axis of axial symmetry XX of the launcher visible in the figures 3 to 5. This axis is at the same time the axis of symmetry of the tree

1 00.

  Thus, in FIG. 3, the pigeon 1 at its extremity rotated towards the trainer 2 a transverse extension 1a (that is to say radial) constitutes the bottom of the bell and makes it possible to connect the parts 1, 1b to one another. Note that the extension 1a is thickened at its rooting zone at the dentee portion 1b constitute the pigeon. Alternatively the extension 1a is slightly inclined towards the trainer and is

  therefore generally transverse orientation.

  The bell pigeon is for example obtained by molding. Advantageously, the bell pigeon is obtained by sintering while being mono

  matter or preferably bi-material.

  The bi-material sintering is very advantageous because we find the same advantages as in FIGS. 4 and 5, namely the choice for the dentee portion of a material shade more specifically adapted to the needs of the gearing with the starter ring (resistance mechanical, wear resistance, low sound emission ...) while the frustoconical part is specially adapted to the needs of the clutch 7

  (resistance to wear, value of the coefficient of friction ...).

  In Figures 4 and 5 the dentee portion 10 is obtained for example by extrusion, sintering, cutting in a bar or stamping. This dentee portion 10 is distinct from the bell 20, which has in these figures a transverse flange 20a centrally hole for passage of the shaft 100 and constitute the bottom bell. This flange 20a is extended at its outer periphery by the frustoconical skirt 20b, itself extended by the tubular extension 20c. The first frustoconical surface is constituted

  by the inner periphery of the skirt 20b.

  In these figures the pigeon 10 comprises a diameter change at its axial end turned towards the drive 2 so that its teeth have an axial length smaller than the inner part of the pigeon-shaped sleeve for sliding along the shaft 100 This sleeve presents

  therefore a tubular portion 10c projecting axially relative to the teeth.

  The axial end of the teeth rotated towards the driver and thus adjacent to the portion 10c forms a transverse shoulder 10a for the flange 20a while the tubular projection 10c of the sleeve has a centering door for the flange 20a. More specifically the inner periphery of the flange 20a is intended to cooperate intimately with the outer periphery of the portion 10c. Alternatively the flange 20a is slightly inclined towards the launcher. In all cases the flange 20a is generally of transverse orientation with respect to the axis X-X axial symmetry of the launcher. The flange 20a is therefore in support of Figure 4 against the shoulder 10a being centered by the portion 10c. Fixing the flange is carried out in this figure by welding the flange 20a on the free end of the portion 10c of the sleeve. The welding is in a form of realization realized in a continuous manner, alternatively in a discontinuous manner. In this figure the welding is represented in black and is of the laser type, of the friction welding type or the arc welding type. In a variant, the attachment is made by crimping, the free end of the part 10c being folded down to

  contact flange 20a as visible for example in 20th in Figure 5.

  For locking in rotation of the flange 20a relative to the pigeon 10 can be provided a knurling intervening between the inner periphery of the flange 20a and the outer periphery of the portion 10c. The knurled piece 20a, 10c is more cured than the other piece 10c, 20a so that furrows wind sizes in the most soft piece when fitting the flange 20a on the part c. Alternatively, the portion 10c has at least one tooth engaged in a complementary manner in an obvious flange or vice versa. Complementary links of the polygonal type can be used. The rotational locking of the bell on the pigeon is therefore performed by

forms cooperations.

  In a variant, it is possible to form bonds by hooping.

  Alternatively, as can be seen in FIG. 5, the metal flange 20a is stamped locally to form at least one depression 20d of slightly larger circumferential width than that of the teeth of the pigeon 10 so that the free end of at least one tooth preferably lodges a mounting clearance in this depression 20d. Only one tooth

  lodges in the depression to cooperate with the lateral edges of it.

  Alternatively, two or more tooth-free ends are lodged in the depression. Preferably, at least two depressions 20d are generally diametrically opposed. The number of depressions depends on the applications and therefore the couple to be transmitted. We will appreciate that the

  connection between the flange and the pigeon is waterproof.

  Of course we can reverse the structures the flange 20a being stamped axially in the other direction to present at least one axial projection penetrating a mounting clearance between two consecutive teeth of the pigeon. All or some of the teeth are used for the rotational stop of the flange

a and so of the bell 20.

  In all cases, an axial and rotational immobilization is obtained.

  the bell compared to the pigeon is a fixation.

  Alternatively, the pigeon 10 is frited and the bell 20, made of solid metal, is mounted, through its flange, has a slight tightening on the portion 10c of the pigeon 10 to remain correctly positioned on the pigeon during manipulations of The assembly thus forms before passing this assembly to the oven for sintering the pigeon. During this passage in the oven the metal of the pigeon swells and thus ensures, in addition to the metallurgical links of the sintering, a definitive immobilization of these two pieces. Connections mentioned above by cooperation of forms, such as a polygonal nesting, can intervene to contribute to the connection in rotation between these two

rooms.

  Alternatively the bell is also frited matter preferably different from that of the pigeon to obtain good friction characteristics. Both pieces are then preassembled before sintering. The swelling coefficient of the pigeon is at least as great as that of the bell so as to maintain a tight contact between

  these two pieces and promote the creation of strong metallurgical links.

  After the sintering, we obtain a monobloc assembly with

  different mechanical characteristics according to the areas considered.

  In one embodiment the dentee portion is obtained by bi-material sintering to obtain on the one hand good sliding properties along the shaft 100 and on the other hand good properties for the gearing.

with the starter crown.

  It is conceivable that this portion dentee 10 is itself in two pieces namely an inner sleeve of a material allowing a good sliding along the shaft 100 and a pigeon mounted on the outer periphery of the sleeve and having a material having good properties for gearing with the starter ring. This can be done in the same way as for assembling the bell with the pigeon. For example the dentee portion is mounted clamping on the sleeve before sintering operation of at least one of these parts. When the two pieces sintered, the coefficient of swelling of the sleeve is at least equal to that of the dentee portion. Alternatively a connection by

hooping is performed.

  In a variant, the sleeve is secured to the bell by being integral with it or fixed thereon. The solution with sleeve

  is advantageous because for a tree size 100 determined on.

  can standardize the sleeve, if necessary with the bell, and adapt the pigeon mounts on the external periphery of the sleeve with each application, in particular as regards its length. We can also position axially as we want the dentee part compared to the sleeve more

  great axial length as the part dentee.

  The bell pigeon is therefore in two or three pieces. It will be noted that the bottom of the bell connects to the skirt thereof, either through a rounded zone, or by means of a frustoconical zone. One can make the same reasoning for the trainer 2 which is therefore in one or more pieces each in different matter to realize optimally its own function. For example, as described in document FR A 2,772,433, the driver may present a metal part, such as a ring provided with at least one flange, attached to the body of the launcher to cooperate with the fork of the mechanical means 14. Figure 1. The aforementioned ring comprises in one embodiment two flanges so that it has a U-shaped section for receiving the fork. As shown in the figures the trainer comprises three portions namely a first portion having at its outer periphery the second frustoconical surface. This first portion extends in axial projection and radial relative to a second portion, constitute the bushing of the driver and having internally the helicoidal grooves adapted to cooperate in a complementary manner with the helicoidal splines of the shaft 100. A ring groove The reception of the range of the mechanical means 14 of FIG. 1 is made at the outer periphery of the second portion. This groove, delimited by two transverse flanks adapted to cooperate with the range of the means 14, belongs to the third portion of the drive 2 and is offset axially with respect to the first portion. This groove extends radially above the grooves of the second portion being more axially running. The second frustoconical surface, advantageously provided with grooves in the aforementioned manner, extends radially projecting from the groove and is connected to the groove via the material lift 4 ', 4 "made in the first portion for accommodating elastic means 3 A frustoconical face relic the concerned end of the second portion at the end of smaller diameter of the second frustoconical surface to reduce the amount of material of the trainer here plastic advantageously reinforced by fibers. against wind wear effected on the two francs delimiting the groove, especially when the range of the mechanical means 14 is metallic.These coatings consist for example of metal washers fixed by overmolding on the sides of the groove, alternatively in half washers or piece U-shaped fixed by snapping on the francs of the throat.In a variant the franc of the groove the furthest away from the pigeon is formed a the favor of a washer reported, all combinations being possible. The second friction surface can also be formed by means of a coating, such as the above-mentioned friction lining, so that the body of the trainer, and thus the second portion thereof, is advantageously made of a material presenting the qualities required to cooperate with the splines of the shaft 100. The trainer 2 alternatively is obtained by sintering in a single material or alternatively in several materials such as pigeon. It will be appreciated that when the bell or the trainer winds in fritted matter it can incorporate therein the desired loads to obtain the desired coefficient of friction for the surfaces 8,8 '. For example, these surfaces may contain copper powder, carbon for example in the form of graphite, silica and molydene. The fork of the means 14 is advantageously plastic to limit the phenomena of incrustation in the trainer and reduce noise. Alternatively the throat and thus the second portion of the trainer can extend radially above the second

  surface 8 'and the skirt of the coupling piece.

  It will be appreciated that one can standardize the trainer and mount on it pigeons of larger radial and / or axial size, as can be seen in FIG. 6. In this case the bottom 1'a is more inclined and has a shape.

  frustoconical to connect the pigeon 1 to the skirt 1 b.

  In this figure, the elastic means with axial action 3 comprise a washer 1 Oa surrounding axially elastic tongues and circumferential orientation bearing on the second stop 4 '. Note that the door 4 "is here slightly inclined so that it is in all cases generally axially oriented The tabs advantageously cambered axially, so that their free end is axially offset from the

washer 10a.

  These tongues 10b here wind annular sector-shaped arms.

  The arms are each connected by a rooting zone 10d to the inner periphery of the washer 10a. The arms have a great circumferential length. By playing on the circumferential length of the arms and on their thickness, the force exerted by the arms on the

second stop 4 '.

  This force is more constant in time than a solution using a wave washer so that the force exerted by the arms 10b on the second stop 4 'at the beginning of the life of the starter is lower than that exerted by a corrugated washer, while respecting the

aforementioned condition> Cd.

  Thus in case of overspeed - internal combustion engine driving the pigeon - the couple residue! transmitted to the electric motor is weaker so that one manages it and the noise resulting from this overspeed, causing an overspeed of the electric motor of the starter,

wind reduced.

  The arms are not bulky axially.

* The arms extend here circumferentially cantilevered from

  and another of a rooting zone 10d.

  Two zones 10d, diametrically opposed and therefore two padres of two arms mounts tete-beche wind expected. The number of zones 10d and

arm 10b depends on the applications.

  According to a characteristic, the washer 10a is split in 1Og. Here the slot 10g is radial and affects one of the zones 10d, so that the elastic means 3 have a circlip and wind function integrated in the circlip of Figure 3, which is mounted in the groove of the extension 1c. By closing the slot 109, which is alternatively inclined, the means are mounted

elastics 3 in said groove.

  Alternatively the axially wind cambered tongues cut

in the slotted washer 10a.

  This reduces the number of pieces to be assembled in final, the means 3

locking everything.

  Alternatively the washer 10a is continuous and a ba70nnette assembly of the precise type. The first stop 4 can be reported and

  less high for mounting the slotted washer 10a.

  In a variant, a mounting is carried out using claws 10e (FIGS. 8 and 9) that engage elastically with the internal periphery of the extension 1c of FIG. 6. In this case, the washer 10a is then continuous and has four arms 10b. and two rooting zones 10d as in FIG. 7. The zones 10d wind circumferentially delimited circumferentially to their outer periphery by two blind slots 110 each connected to a claw 10 e projecting radially from the outer periphery of the the washer 10a. The height of these claws is weak here. These claws 10th wind connected to each other by a trunk, one flat 111 delimiting the

  external periphery of a rooting zone 1 Od.

  The wind claws delimited each by the edge of a slot 110, a trunk, which is rectilinear, constitute the outer periphery of the claw 10e and a

  tron, con incline connection to the trunk, it flat 111.

  Each rooting zone 10a thus has at its outer periphery a tongue 112 which is less wide circumferentially than said zone d. Each tongue 112 has at each of its ends a

  claw 1 Oe. Tongues 112 may flex axially.

  The external diameter of the claws 10e is slightly greater than the internal diameter of the extension 1c so that when axially fitted the elastic means in the extension 1c the tongues bend axially so that the claws remain in pressurized engagement with the internal bore of the internal extension 1 c as shown in Figure 9. When the elastic means 3 wind ['object of a force acting in the opposite direction to that of the fitting, the elastic means are blocked by buttresses. The tabs 112 have the overall shape

  of a cat's head with two ears formed by 10th claws.

  The groove of FIG. 6 can be removed. As a variant, the groove is retained so that the axial locking of the elastic means 3 is improved. In a variant, the groove is replaced by depressions of reception

10th claws.

  Advantageously the claws 10 e wind mounted under pressure in the groove or depressions to avoid any movement due to vibrations.

  As can be seen from the description and the drawings,

  increases the torque transmission capacity of the launcher due to a large mean diameter of friction for a given diametral bulk. Here the average diameter of friction, and thus of contact of frustoconical friction surfaces 8,8 'is equal to or greater than 75% of the internal diameter of the tubular extension 1c, 20c. It also reduces the number of parts as well as the axial and diametral size of the launcher. Good waterproofness is obtained with regard to projections of oil or water directed towards the pigeon by means of the bell. It is possible to choose different materials, one well adapted to the mechanical characteristics required by the pigeon, the other being well adapted to the needs of friction

  and wear resistance of the conical clutch.

  Advantageously, an electronic control device is used for the electrical supply of the winding 12a and the electric motor of the starter to reduce the duration of the "freewheeling" phase of the conical clutch and to overcome the reaction time of the driver. For example, the electronic device is of the type described in document FR A 2 795 884 supplying the winding 1 2a via a transistor according to a << <<

  Pulse Width Modulation >> (PWM) in French.

  More precisely, the effective current in the winding 12a is varied during displacement of the core 12b towards its contact position, to close the movable contact 13 and supply the electric motor M. During this displacement, it is possible to adopt: - a first phase of training with an effective current sufficiently high to put the nucleus 1 2b in motion, puts, - a second phase of training with a lower effective current, - one puts in cauvre, during the second phase, after a predetermined or determined time, a continuous increase in

Effective intensity.

  For more details, please refer to this document.

  Thanks to the electronic device it is possible to choose a less noble friction material for the friction surfaces 8, 8 'because it is better to control the overspeed phase and therefore slip between the two surfaces. We

thus reducing costs.

  Advantageously, to house the conical clutch launcher, a torsion damper has elastic means with circumferential action eVou

  a wind limiter torque variant associated with the launcher.

  Thus, in a first embodiment, the torsion damper and the wind torque limiter associated with the epicyclodal gear reducer of FIG. 1 interpose between the electric motor and the output shaft 100 on

which is the trainer 2.

  For this we can adopt for example the solution described in the document FR 99 16726 filed 30112/1999. The torque limiter is then interposed axially between the gearbox crown and a flange

  a box inside which rotates the crown.

  The elastic means then consist of at least one elastically deformable damping block, for example being made of elastomer, which rotatably connects a disk belonging to the torque limiter. In a variant, the starting ring belongs to the secondary mass of a damping flywheel connected to the gearbox of the motor vehicle. This secondary mass is connected by a torsion damper and a torque limiter to a primary flywheel connected to the crankshaft of the

  vehicle as described in document FR A 2 598 475.

  Alternatively the two devices mentioned above can be provided.

  As a variant, only one of them constitutes a torque limiter.

torsion damper is present.

Claims (6)

  Motor vehicle starter comprising a launcher equipped with a pigeon (1.10), comprising a geared portion for gearing with a starter ring, a drive trainer (2) provided with splines for gearing with complementary splines carried by an output shaft (100) driven in rotation by the electric motor (M) presented by the starter and a coupling device for coupling the pigeon (1,10) to the driver (2), characterized in that the pigeon (1,10) comprises at least one piece of fritted material and in that the coach (2) comprises at least one piece of plastic, in particular a piece of material plastic reinforced with fibers.   2. Starter according to claim 1, characterized in that the pigeon comprises a sintered bi-material shaped portion to obtain, on the one hand, good sliding property along the output shaft (100) and, d on the other hand, to obtain good properties for   training with the starter crown.   3. Starter according to claim 1, characterized in that the dentee portion (10) is in two pieces, at least one of which is in a sintered material, namely an inner sleeve of a material allowing a good sliding along the output shaft (100) and a piece presenting the teeth of the pigeon (10), on the one hand, mounted on the outer periphery of the sleeve and, on the other hand, in a material having good properties for   the gear with the starter ring.   4. Starter according to claim 3, characterized in that the sleeve and the piece having the teeth of the pigeon (10) wind sintered material and in that the coefficient of swelling of the sleeve is at least equal to that of the pigeon.   Starter according to any one of the claims   precedents, characterized in that the coach (2) is in several pieces each of different material and in that at least one of the pieces is in plastic.   6 Starter according to any one of the claims   preceding, characterized in that the coupling device comprises a conical clutch (7)) comprising a first frustoconical friction surface (8), cited first surface, integral with the pigeon (1,10) and surrounding at least in part a second frustoconical friction surface (8 '), cites a second surface of complementary shape to the first surface (8) and integral with the drive (2), in that the coupling device comprises a form coupling part hollow having a bottom extended by an annular skirt directed axially towards the drive (2), in that the first surface (8) is borne internally by the skirt (1b, 20b) of the coupling piece and in that the bottom (1a, 1'a, 20a) of the coupling piece is integral with the pigeon (1, 10) 7 Starter according to claim 6, characterized in that the axial end of greater diameter of the second surface (8 ' ) is delimited by a transverse shoulder carrying a second abutment (4 ') for implantation axial ssion of elastic means with axial action (3) between this second stop (4 ') and a first stop (4) carried   by the free end of the skirt of the coupling.   8. Starter according to claim 6 or 7, characterized in that the   hitch is in matter frittee.   9. Starter according to claim 8, characterized in that the fixing of the bottom (20a) of the coupling piece on the pigeon is carried out by   swelling of the pigeon during a sintering operation.   Starter according to one of Claims 6 to 9,   characterized in that the drive (2) has a first portion carry the second friction surface (8 '), in that the first portion is offset axially and radially from a second portion provided with splines for gearing with splines   complementary carried by the output shaft (100).